From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Flywheel gear cutting and specifications for ordering Bijur drive test samples.
| Identifier | ExFiles\Box 40\5\ Scan072 | |
| Date | 16th December 1921 guessed | |
| -5- of our device are cutting the flywheel teeth directly in the cast iron flywheel, and do not use a separate steel gear ring. In order that this may be done, it is however necessary that the cast iron making up the flywheel have a minimum tensile strength of twenty-thousand pounds per square-inch. TEST SAMPLES. The Bijur drive is made with pinions of 9, 10, 11, 12 or 13 teeth, which may be supplied in either Module 3 or 8-10 pitch (module 3.174). It is made in two sizes, namely, with a barrel of 2 and of 2-1/2 inches diameter. The difference between the two sizes is that the larger one is fitted with a friction clutch of higher slipping torque. The larger size is therefore used by us for the larger and stiff engines only. All of the above pinion sizes can be supplied with the 2-1/2" drive, while all but the 13-tooth pinion can be furnished with the 2" drive. The Bijur drive is made for either direction or rotation, and for either outboard or inboard mesh, that is, with the pinion moving away from the starter or toward it when entering into mesh with the engine flywheel. Regarding the sample apparatus which you request me to send to you for testing purposes, I am sorry to say that all of the samples which I had on hand with me are at present time under test in various plants. Sample apparatus for you will therefore have to be shipped to you directly from our factory in America. This can be done upon cable instructions from me, and will involve a very short delay only in the delivery of the samples. Before cabling to our factory for ordering your samples, I would like to know exactly what type of apparatus would best suit you for your tests. This information, which I would thank you for sending me as soon as possible in order to avoid all unnecessary delay, should mention the following details:- Number of teeth on flywheel gearing. Number of teeth on starter pinion. Are teeth to be Module 3 or 8-10 pitch? Does the starter pinion move away from the starter or toward the starter when entering into mesh with the engine flywheel? What is the direction of rotation (clockwise or anti-clockwise) of the starter when standing at the starter driving end and looking at the starter? contd:- | ||